Blogs

Our El Niño is still hanging around, and forecasters think it’s likely to stay through the summer. What happens after that is less clear, though, with about a 50% chance of El Niño continuing through the fall and winter. Things as they are The sea surface temperature across much of the tropical Pacific is still warmer than average, with the Niño3.4 Index coming in at 0.64°C above average during May (via ERSSTv5). The atmosphere also reflected weak El Niño during May, and both the Southern Oscillation Index the Equatorial Southern Oscillation Index were moderately negative. When these indexes are negative, it means the surface air pressure over the far western Pacific is higher t…   Read article

A few weeks ago, NCEI updated its U.S. climate trends maps with the data from 2018. Most months and places are getting warmer over time, especially over the very long (century scale) term. But some regions and seasons are not changing in lock-step with the big picture. For January, considering all 124 years spanning 1895 through 2018, much of the South and Mid-South has cooled slightly. That regional/seasonal exception to the rule is a feature of and testament to the complexity of the climate system. We’re going to look at January trends to tease out some nuances with how these trends are computed. Let’s go Beyond the Data. Linear trends: the duct tape of statistics …   Read article

We’ve talked a lot about how ENSO impacts weather and climate around the world on this blog, but did you know that ENSO also could affect your health? In fact, ENSO can affect outbreaks of a variety of diseases, including cholera, Chikungunya, Zika, Rift Valley fever, and plague (yes, that infamous, Medieval-times kind of plague!). A multi-organization team of scientists (1) led by Dr. Assaf Anyamba of the Universities Space Research Association (USRA) at NASA Goddard Space Flight Center recently combined this disease knowledge with seasonal ENSO predictions to issue early warnings for possible disease outbreaks throughout the globe. These alerts proved to be quite accurate during the gre…   Read article

Borrowing one of meteorology’s great euphemisms, this spring has been “an active one” in much of the country. The Plains and Upper Midwest experienced huge events in back-to-back months. March brought an explosive winter storm to much of the region, and a cascade of events that led to historic flooding from Nebraska to Wisconsin. April gave us a more canonical blizzard, a winter storm with snowfall measured in feet. So what happened? How does this fit into history? How does April bring the huge storms? Some answers follow. Let’s go Beyond the Data. The March Cyclone and Floods Understanding what happened in March requires going back several weeks in time to examine the condition…   Read article

Forecasters estimate a 70% chance that our current El Niño will continue through the summer, and a 55-60% chance it will extend into the fall. Just a number El Niño conditions were still evident across the tropical Pacific Ocean during April, as the sea surface temperature in the Niño3.4 region averaged about 0.7°C warmer than the long-term average (via the ERSSTv5 database). Most computer models predict that the ocean surface will stay warmer than average in the Niño3.4 region, with the majority of predictions remaining above the El Niño threshold of 0.5°C through next fall. However, there is a broad range of potential outcomes shown here, and we’re still within the spring pred…   Read article